In the oil and gas industry, hydrocarbons are produced from wellbores traversing subterranean hydrocarbon producing formations. Many current well completions include more than one wellbore. For example, a first, generally vertical wellbore may be initially drilled within or adjacent to one or more hydrocarbon producing formations. Any number of additional wellbores may then be drilled extending generally laterally away from the first wellbore to respective locations selected to optimize production from the associated hydrocarbon producing formation or formations. Such well completions are commonly referred to as multilateral wells.
A typical multilateral well completion includes a primary wellbore defined in part by a string of casing and cement disposed between the casing and the inside diameter of the primary wellbore. The primary wellbore extends from the well surface to a desired downhole location, and directional drilling equipment and techniques may then be used to form one or more exits or windows from the primary wellbore through the casing and cement at predetermined locations and subsequently drill one or more corresponding secondary wellbores that extend from the primary wellbore. For many well completions such as deep offshore wells, multiple secondary wellbores will be drilled from each primary wellbore in an effort to optimize hydrocarbon production while minimizing overall drilling and well completion costs.
Selective isolation and/or reentry into each of the secondary wellbores is often necessary to optimize production from the associated hydrocarbon producing formations. A typical multilateral well completion will have a reentry window assembly (alternately referred to as a lateral reentry window) installed within the primary wellbore at the junction between the primary wellbore and each secondary wellbore. Each reentry window assembly includes a window that provides access into the secondary wellbore from the primary wellbore. An isolation sleeve is arranged within the reentry window assembly and is selectively movable to cover or expose the window. To enter the secondary wellbore, the isolation sleeve is located and moved axially within the reentry window assembly to expose the window and allow access into the secondary wellbore.